I believe a lot of drops are no longer as random as they used to be, remember in the last major patch they said that drops would be associated with the group makeup and so could drop more cloth if there were a lot of cloth users?
If they tweaked the drop rates to match to players it has taken a lot of randomness out of the drops BUT the weird thing I have seen is that I see a lot of the same drops every time I run a dungeon and in particular in ICC 5 mans a LOT of plate drops.

So based on the original point of drops being aimed at the group makeup, then with a boxer they are going to see more of the same drops due to the group always being the same and in a random pug you are more likely to see more variety in the drops.